Originally Posted by What Sex Means for World Peace

In fact, the very best predictor of a state's peacefulness is not its level of wealth, its level of democracy, or its ethno-religious identity; the best predictor of a state's peacefulness is how well its women are treated. What's more, democracies with higher levels of violence against women are as insecure and unstable as nondemocracies.

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The evidence of violence against women is clear. So what does it mean for world peace? Consider the effects of sex-selective abortion and polygyny: Both help create an underclass of young adult men with no stake in society because they will never become heads of households, the marker for manhood in their cultures. It's unsurprising that we see a rise in violent crime, theft, and smuggling, whereby these young men seek to become contenders in the marriage market. But the prevalence of these volatile young males may also contribute to greater success in terrorist recruiting, or even state interest in wars of attrition that will attenuate the ranks of these men. For instance, the sole surviving terrorist from the 2008 Mumbai attacks testified that he was persuaded by his own father to participate in order to raise money for the dower that he and his siblings needed in order to marry.

We also know through experimental studies that post-conflict agreements that are negotiated without women break down faster than those that do include women, and that all-male groups take riskier, more aggressive, and less empathetic decisions than mixed groups -- two phenomena that may lead to higher levels of interstate conflict.